As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
High current information handling system loads, such as for CPU's and memory, typically require multi-phase voltage regulators (VR's). An integrated power stage (IPstage) of each VR phase is an integrated circuit that is usually composed of a MOSFET (metal oxide semiconductor field effect transistor) driver, a high-side MOSFET, and a low-side MOSFET. FIG. 2 illustrates a block diagram of a conventional smart IPstage 250. IPstage 250 includes modules that consume power when a VR system is lightly or very lightly loaded. These modules include driver logic module 252, high frequency current sense/calibration module 254, and half-bridge power MOSFETs module 256 (including high side and low side FETs). In addition to an IPstage, a VR phase also usually includes an inductor with all the phase inductors being tied together at their output. One example of a multi-phase VR architecture may be found in U.S. Pat. No. 7,999,520.
Servers are a type of information handling system that is requiring ever increasing accuracy for power telemetry data to be used in system level power and thermal management algorithms. Modern design of servers and other types of information handling systems requires accurate load current reporting in real-time manner as well as good light load power efficiency. Current sense accuracy directly impacts system performance, power saving and reliability. Inductor direct current resistance (DCR) sense has been widely used in power industry for many years. One possible approach on improving accuracy is to use integrated smart power stage (SPS or IPstage) with RDS(on) current-sensing and calibration. Smart IPstages and other changes in multi-phase VR system designs to meet changing requirements for current sense accuracy bring complexity to the power stage and thus induce higher quiescent current demand in IPstage module.